No association of the dopamine D2 receptor genetic bilocus score (rs1800497/rs1799732) on food addiction and food reinforcement in Chilean adults.

Purpose: Different systems regulate food intake. In the reward system, dopamine (DA) is the main neurotransmitter, and a variety of genetic variants (rs1799732 and rs1800497) are associated with addiction. Addiction is a highly polygenic disease, where each allelic variant adds a small amount of vulnerability. Polymorphisms rs1799732 and rs1800497 are associated with eating behavior and hedonic hunger, but links to food addiction remain unclear. Aim: To evaluate the association between the bilocus profile (rs1799732-rs1800497) of the dopaminergic pathway with food reinforcement and food addiction in Chilean adults. Methods: A cross-sectional study recruited a convenience sample of 97 obese, 25 overweight, and 99 normal-weight adults (18-35 years). Anthropometric measurements were performed by standard procedures and eating behavior was assessed using the: Food Reinforcement Value Questionnaire (FRVQ) and Yale Food Addiction scale (YFAS). The DRD2 genotypes were determined by TaqMan assays (rs1800497 and rs1799732). A bilocus composite score was calculated. Results: In the normal weight group, individuals who were heterozygous for the rs1977932 variant (G/del) showed higher body weight (p-value 0.01) and abdominal circumference (p-value 0.01) compared to those who were homozygous (G/G). When analyzing rs1800497, a significant difference in BMI was observed for the normal weight group (p-value 0.02) where heterozygous showed higher BMI. In the obese group, homozygous A1/A1 showed higher BMI in comparison to A1/A2 and A2/A2 (p-value 0.03). Also, a significant difference in food reinforcement was observed in the rs1800497, where homozygous for the variant (A1A1) show less reinforcement (p-value 0.01).In relation to the bilocus score in the total sample, 11% showed "very low dopaminergic signaling", 24.4% were "under", 49.7% showed "intermediate signaling", 12.7% showed "high" and 1.4% showed "very high". No significant genotypic differences were observed in food reinforcement and food addiction by bilocus score. Conclusions: The results indicate that the genetic variants rs1799732 and rs1800497 (Taq1A) were associated with anthropometric measurements but not with food addiction or food reinforcement in Chilean university students. These results suggest that other genotypes, such as rs4680 and rs6277, which affect DA signaling capacity through a multilocus composite score, should be studied. Level V: Evidence obtained from a cross-sectional descriptive study.

Association of the dopamine D2 receptor rs1800497 polymorphism with food addiction, food reinforcement, and eating behavior in Chilean adults.

PURPOSE: The regulation of food intake and body weight involves two interacting systems: (a) The homeostatic system (including biological regulators of hunger and satiety) and (b) the non-homeostatic system, (involving concepts of food reinforcement and food addiction). Studies have established a strong genetic component in eating behavior and obesity. The TaqI A1 polymorphism (rs1800497) has previously been associated with eating behavior, diminished dopamine D2 receptor (DRD2) density, higher body mass, and food reinforcement, but relations to food addiction remain unclear. AIM: To evaluate the association between the polymorphism rs1800497 with eating behavior, food reinforcement and food addiction in Chilean adults. METHODS: This cross-sectional study recruited a convenience sample of 97 obese, 25 overweight and 99 normal-weight adults (18-35 years). Anthropometric measurements were performed by standard procedures. Eating behavior was assessed using the: Yale Food Addiction Scale (YFAS), the Three Factor Eating Behavior Questionnaire and the Food Reinforcement Value Questionnaire (FRVQ). The DRD2 genotype (rs1800497) was determined by taqman assays. RESULTS: Twenty-two percentage of the participants met the criteria for food addiction. Food addiction was higher in women than men (26% vs 10.7%) and in obese compared to non-obese (40% vs 6%). There was no relationship between food addiction and DRD2 genotype. However when stratified by sex and nutritional status, obese female carriers of the A1 allele reported greater scores on emotional eating and snack food reinforcement compared to non-carriers. CONCLUSIONS: The DRD2 polymorphism is associated with some hedonic aspects of eating behavior, namely food reinforcement and emotional eating but not food addiction, and this association may be moderated by sex and obesity status, with obese women who are carriers of this genetic variant at higher risk. LEVEL OF EVIDENCE: Level V: evidence obtained from a cross-sectional descriptive study.

Genetic variation of the dopamine D2 receptor gene: association with the reinforcing value of food and eating in the absence of hunger in Chilean children.

INTRODUCTION: Background: food is a powerful reinforcer that motivates people to eat. The TaqI A1 polymorphism (rs1800497; T>C) downstream of the dopamine D2 receptor (DRD2) gene has been associated with diminished DRD2 receptor density, higher food reinforcement, and impaired eating behavior in adults. Objective: to evaluate the association between the rs1800497 polymorphism and the reinforcing value of food and eating in the absence of hunger in Chilean children. Material and method: nineteen Chilean children (aged 8-12 years) who were carriers of the A1-allele and 19 age- and gender-matched non-carriers (A2-allele) were evaluated on the reinforcing value of food and eating in the absence of hunger. Anthropometric measures were performed by standard procedures. Briefly, children received a standard pre-load lunch followed by an ad-libitum exposure to palatable foods. Results: no differences were found between A1-allele carriers and non-carriers, whether obese or non-obese, in ad libitum energy intake, macronutrient consumption, or the relative reinforcing value of food (p > 0.05). In obese children, A1 carriers reported significantly lower satiety and fullness before lunch (p < 0.05). However, in children with normal weight A1 carriers were found to exhibit trends for greater satiety and fullness before lunch when compared to non-carriers, but this trend reversed after lunch such that carriers exhibited lower satiety and fullness (p = 0.06). Conclusions: although TaqI A1 may play an important role in some eating behavior-related traits such as satiety and fullness, especially in obese children, our findings indicate that this polymorphism does not appear to affect eating in the absence of hunger or food reinforcement in children.

INTRODUCCIÓN: Antecedentes: los alimentos son un poderoso reforzador de la alimentación. El polimorfismo TaqI A1 (rs1800497; T> C) del gen del receptor 2 de dopamina (DRD2) se ha asociado con una menor densidad de DRD2, un mayor refuerzo alimentario y un comportamiento alimentario alterado en adultos. Objetivo: evaluar la asociación entre el polimorfismo rs1800497, el valor reforzador del alimento y la conducta de comer en ausencia de hambre en niños chilenos. Material y método: treinta y ocho niños chilenos, 19 portadores del alelo A1 y 19 no portadores (alelo A2), pareados por genero y edad, fueron evaluados en condiciones de laboratorio para determinar el valor reforzador del alimento y la conducta de comer en ausencia de hambre. Las mediciones antropométricas se realizaron por procedimientos estándar. Brevemente, los niños recibieron un almuerzo estándar seguido de una exposición ad-libitum a alimentos sabrosos. Resultados: no hubo diferencias en la ingesta ad libitum de energía, ni en el consumo de macronutrientes, ni en el valor reforzador del alimento entre los portadores del alelo A1 frente a los no portadores (p > 0,05). Entre los niños obesos, los portadores del alelo A1 reportaron un menor nivel de saciedad y plenitud pre-almuerzo (p < 0,05). Sin embargo, entre los niños con normopeso se observó que los portadores de A1 tenían tendencia a presentar un mayor grado de saciedad y plenitud (pre-almuerzo) frente a los no portadores. Esta tendencia se invirtió post-almuerzo, de modo que los portadores exhibieron menor saciedad y plenitud (p = 0,06). Conclusiones: la variante TaqI A1 podría desempeñar un papel importante en algunos rasgos relacionados con la conducta alimentaria, como la saciedad y la plenitud.

Development of the Ottawa Disordered Eating Screen for Youth: The ODES-Y.

OBJECTIVE: To develop a concise screening tool that allows for early identification of disordered eating in youth. STUDY DESIGN: In this 2-step classification accuracy study, questions for the Ottawa Disordered Eating Screen-Youth, a 2-question screening tool (index test), were conceptualized by clinician-scientists from tertiary care pediatric eating disorder and weight-related clinics, and was validated using retrospective data (2004-2010) from a community-based study, the Research on Eating and Adolescent Lifestyles (REAL) study. RESULTS: Analyses of contrast between the index test and the reference standard using data from 2892 (1714 females) students between grade 7 and grade 12 revealed classification statistics of 67.1% for sensitivity, 85.9% for specificity, 4.7 for positive likelihood ratio, 0.38 for negative likelihood ratio, 50.6% for positive predictive value, and 92.4% for negative predictive value for females and 61.1% for sensitivity, 93.9% for specificity, and 9.9 for positive likelihood ratio, 0.41 for negative likelihood ratio, 32.3% for positive predictive value, and 98.0% for negative predictive value for males. CONCLUSIONS: Our findings suggest that the index test has utility as a short and accurate screening tool for earlier detection of disordered eating thoughts and behaviors in youth. Additional research is needed to best determine how the index test can be administered to youth across various health care, school, public health, and surveillance settings in clinically sensitive pragmatic ways.

Association of the FTO fat mass and obesity-associated gene rs9939609 polymorphism with rewarding value of food and eating behavior in Chilean children.

OBJECTIVES: The aim of this study was to assess the association between the single-nucleotide polymorphism rs9939609 in the FTO gene and homeostatic/non-homeostatic eating behavior patterns in Chilean children. METHODS: A cross-sectional study was conducted in 258 children (44% female; 8-14 y of age). Anthropometric measurements (weight, height, Z-score of height, body mass index, and waist circumference) were performed. Eating behavior was assessed using the Eating in Absence of Hunger Questionnaire; the Child Eating Behavior Questionnaire; the Three Factor Eating Questionnaire, and the Food Reinforcement Value Questionnaire. Genotype of rs9939609 was determined by a Taqman assay. Association of rs9939609 with eating behavior was assessed using non-parametric tests. RESULTS: Allelic frequencies of rs9939609 were estimated as 77% for the A allele and 23% for the T allele. We found that normal-weight girl A carriers had higher scores of Satiety Responsiveness and Slowness on the Eating subscale. Normal-weight boy A carriers showed significantly higher scores on the Negative Affect and lower scores of the Desire to Drink subscale. In overweight children, A carriers showed higher scores on the Food Responsiveness, Emotional Overeating, Enjoyment of Food, and Food Choice subscales and lower scores on the Satiety- Responsiveness and Slowness in Eating subscales. In obese children, we found higher scores on the Cognitive Restrained subscale and lower Food Choice. CONCLUSION: The rs9939609 A allele of the FTO gene is associated with eating behavior traits and may predispose to obesity.

Effects of a Preschool Intervention on Physical Activity and Body Composition.

OBJECTIVE: To investigate the effect of a preschool physical activity intervention program delivered in licensed childcare settings, with or without a parent-facilitated home component, on children's daily physical activity, sedentary time, and body composition. STUDY DESIGN: For this cluster randomized controlled trial, 18 childcare centers were randomly allocated in equal numbers to the typical curriculum comparison group, childcare intervention alone (CC), or childcare intervention with parental involvement. Accelerometers were used to asses physical activity and sedentary time, and body composition was measured by bioelectrical impedance. RESULTS: Linear mixed model regression analyses showed no differences between the CC, the childcare intervention with parental involvement, and the comparison groups in changes from baseline to 6 months in total physical activity (P for time × group interaction = .665) or moderate-to-vigorous physical activity (P for time × group interaction = .164) when adjusted for baseline physical activity levels. Furthermore, no group differences were found for changes in light physical activity, sedentary time, or anthropometric variables. CONCLUSIONS: An affordable and easily scalable preschool intervention program delivered in licensed childcare settings, with or without the addition of a parent-driven home physical activity promotion, seems to have no significant effect on physical activity, sedentary time, or body composition. TRIAL REGISTRATION: ISRCTN: ISRCTN94022291.

Association of the dopamine D2 receptor rs1800497 polymorphism and eating behavior in Chilean children.

OBJECTIVES: Studies have established a strong genetic component in eating behavior. The TaqI A1 polymorphism (rs1800497) has previously been associated with obesity and eating behavior. Additionally, this polymorphism has been associated with diminished dopamine D2 receptor (DRD2) density, higher body mass, and food reinforcement. The aim of this study was to evaluate the association between the DRD2 rs1800497 polymorphism and eating behavior in Chilean children. METHODS: This was a cross-sectional study in which we selected 258 children (44% girls, 56% boys; ages 8-14 y) with a wide variation in body mass index. Anthropometric measurements were performed by standard procedures. Eating behavior was assessed using the Eating in Absence of Hunger Questionnaire (EAHQ), Child Eating Behavior Questionnaire, and the Food Reinforcement Value Questionnaire. Genotype of the rs1800497 was determined by polymerase chain reaction-restriction fragment length polymorphism. Association of the TaqI A1 variant (T allele) with eating behavior was assessed using nonparametric tests. RESULTS: Compared with normal-weight children, the obese group demonstrated higher scores on the External Eating and Fatigue/Boredom subscales of the EAHQ. Higher scores were assessed in Food Responsiveness, Emotional Overeating, Enjoyment to Food and Desire to Drink subscales (P < 0.001) and lower scores of the Satiety Responsiveness and Slowness in Eating (P < 0.05). In the sex-specific analysis, the TaqI A1 allele was associated with higher scores on Satiety Responsiveness and Emotional Undereating subscales in obese girls, and higher scores of Enjoyment of Food subscale in boys. CONCLUSION: The TaqI A1 polymorphism may be a risk factor for eating behavior traits that may predispose children to greater energy intake and obesity.

Physical activity and sedentary behavior in obese youth.

OBJECTIVE: To determine whether directly measured physical activity and sedentary behavior patterns of obese children presenting to a weight-management clinic differs from nationally representative samples of obese and normal-weight children. STUDY DESIGN: A cross-sectional comparison study of 3 groups of boys and girls between 8 and 18 years (mean, 13.4 years) was performed. A clinical group (n=56) seeking specialized care for obesity was compared with 2 nationally representative samples of children from the Canadian Health Measures Survey (CHMS): (1) body mass index>95th percentile (n=143); and (2) body mass index<85th percentile (n=958). RESULTS: Obese clinical and obese CHMS boys did not differ in daily moderate-to-vigorous physical activity (MVPA). Both obese groups engaged in less MVPA than normal-weight boys in the CHMS (P<.0006). Compared with normal-weight boys, obese boys had fewer days in which they accrued 60 or 30 minutes of MVPA (P=.006 and .01, respectively). Daily MVPA did not differ among the 3 groups of girls. Light activity in clinical boys was lower than in the normal weight CHMS boys, whereas clinical girls engaged in less light activity than both CHMS comparators. No differences were observed between groups for sedentary behavior. CONCLUSIONS: Obese youth, whether in clinic or the community, were not more sedentary than their normal-weight CHMS comparators. Although obese youth were less active, overall MVPA was low in all groups. This finding highlights the need for health professionals to target both physical activity and sedentary behavior in all children, rather than focusing on only children with obesity.